1. Field of the Invention
The field of the present invention is slide members and more particularly, improvement in slide members of the type having a surface layer of a Pb alloy on a slide surface for a mating member.
2. Description of the Prior Art.
There are conventionally known slide bearings as a slide member of such type, comprising a surface layer formed of a Pb-Sn based alloy (see Japanese patent Application Laid-open No. 96088/81).
Such a slide bearing has been applied to a journal portion of a crankshaft in an engine, an enlarged end of a connecting rod, or the like. Under existing circumstances where there is a tendency of increasing in speed and output of an engine, however, the prior art slide members suffer from a problem that they merely show a poor seizure resistance at the surface layer thereof. This is primarily due to the crystal form of Pb-Sn based alloy forming the surface layer; the crystal form being a form with crystal faces oriented at random. In addition, from a viewpoint of improvement in seizure resistance, it is necessary to improve the oil retension characteristic of the surface layer.